608-36-6Relevant articles and documents
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Lohaus,Gussmann
, p. 294,296, 298 (1936)
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Method of treating DBA mother liquor
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Paragraph 0048-0058, (2020/04/02)
The present invention relates to a method of treating a DBA mother liquor, wherein a small amount of a reagent is used, high DBA yield is provided, and waste is less.
Preparation method of 1,3-dibenzyl-2-oxoimidazolidine-4,5-dicarboxylic acid
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Paragraph 0046; 0047; 0054; 0055; 0058-0063, (2017/08/30)
The invention relates to a preparation method of 1,3-dibenzyl-2-oxoimidazolidine-4,5-dicarboxylic acid, comprising the steps of subjecting fumaric acid, bromine and hydrobromic acid to additive reaction to generate meso-2,3-dDibromosuccinic acid, subjecting the meso-2,3-dDibromosuccinic acid, benzylamine and a strong base to aminating reaction to generate dibenzylamino salt, subjecting the dibenzylamino salt and triphosgene to cyclization to generate the 1,3-dibenzyl-2-oxoimidazolidine-4,5-dicarboxylic acid. The fumaric acid is subjected to addition, and then substitution and cyclization are performed to obtain the 1,3-dibenzyl-2-oxoimidazolidine-4,5-dicarboxylic acid, and detection shows that HPLC (high-performance liquid chromatography) content of the 1,3-dibenzyl-2-oxoimidazolidine-4,5-dicarboxylic acid may reach 98-99%. The preparation method has the advantages that hydrobromic acid is added for bromination additive reaction, the concentration and reaction temperature of the hydrobromic acid are optimized, and bromine loss is more reduced; amination mother liquid is used in amination, the cost is saved, and product yield is increased; in ring-closure reaction, pH and reaction product concentration are decreased, the yield of the 1,3-dibenzyl-2-oxoimidazolidine-4,5-dicarboxylic acid is increased greatly, and the quality of the 1,3-dibenzyl-2-oxoimidazolidine-4,5-dicarboxylic acid is improved; experiments verify that through process innovation, production cost is reduced greatly, production efficiency is improved, and the process is energy efficient and environmentally friendly.